I have the Pantac version of the WSH chest rig and I have used it in indoor/cqb games.
I like the fit and I am a big dude, 250 lbs big, it has room for everything I need and it is easy for me to access what I need on it.
Also when I bought it my plan was to run an M4, however so far I have only gamed with a MP5 and a MP7, and I had no problems fitting MP5 and MP7 magazines in the built in pouches even though they were made for M4 magazines.
The down side is that if you do not fill in the built in magazine pouch and just decide to add MOLLE pouches to it then those pouches will really sag.
The RRV allows you to add the pouches you want and when that setup is no longer viable you can change the setup by moving around pouches and/or adding new pouches.
A Canadian is someone who knows how to make love in a canoe - Pierre Berton